![]() ![]() But library authors may find it useful as a way to engage stronger type checking and better capture design intent. Most developers probably won't bother with this for application and domain code. And it provides a similar hint to readers that this member is going to be used by serialization. The annotation lets you make a similar kind of assertion: that you intend that this is one of those magic serialization members (fields and methods), and if it does not match the profile, the compiler should alert you with an error. What does is assert that "I think this is an override, if I am mistaken, please tell me in the form of a compilation error." And it serves as notice to readers of the code that this method is not new with this class.īecause serialization uses "magic" method and field names (methods like readObject are not part of any interface, they are just magically given significance by serialization), and the determination of whether the magic works is tricky (methods must not only have the right name and arguments, but the right accessibility and static-ness), it is easy to declare a method that you think is meant to be used by serialization, but for which serialization doesn't agree. The annotation does not make a method declaration an override of another - that is handled by the language based on comparing names, signatures, and accessibility between the method and methods in the supertype(s). It is analogous in this way to the annotation, which exists purely to capture design intent, so that humans and tools have more information to work with. This annotation exists purely to engage better compile-time type checking. If the signature of a method does not match, or the modifiers are wrong, you will catch the problem before serialization fails at runtime. Or the wrong access modifier // compile-time error, must be void writeObject(java.io.ObjectOutputStream out) throws IOExceptionīasically, something annotated with this must exactly match the descriptions of the 7 applicable elements mentioned in the JavaDoc (5 methods, 2 fields). Like it is optional and is supposed to give some compile-time assurance for problems which might otherwise not be caught until runtime.įor example, misspelling serialVersionUID: static final long seralVersionUID = 123L // compile-time error, should be 'serialVersionUID' data streams over computer networks) and reconstructed later (possibly in a different computer environment). ![]() files in secondary storage devices, data buffers in primary storage devices) or transmitted (e.g. It has no way to influence runtime behaviour (besides possibly compile-time code generation, which does not happen). In computing, serialization (or serialisation) is the process of translating a data structure or object state into a format that can be stored (e.g. The bytecode will contain no trace of it. Its retention is 'source', so it's discarded after compilation. When an object is serialized, information that identifies its class is recorded in the serialized stream. The Object Serialization Specification describes object serialization in detail. What I don't understand, does the annotation affect the A (Java) class can override this default serialization and define its own way of serializing objects of that class. ![]()
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